水土保持植物苗期根系特征及其对黑土团聚体稳定性的影响OA

To quantify the differences in quantitative root traits of major soil and water conservation plants at the seedling stage and their effects on soil aggregate stability of cultivated black soil,this study selected six plant species grown in outdoor pots for 4 years as research objects,including arbor species(Populus simonii×P.nigra,Pinus sylvestris var.mongolica Litv.),shrub species(Ribes nigrum,Rubus sachalinensis)and herbaceous species(Thalictrum squarrosum,Medicago sa-tiva).The root morphological trait indices(root length density,root surface area density)and soil aggregate stability indi-ces(water-stable aggregate composition,mean weight diameter,fractal dimension,aggregate destruction rate)were sys-tematically determined.The results showed that the root systems of all plant species at the seedling stage were dominated by fine roots with a diameter<2 mm.The root length density and root surface area density of fine roots and small roots of R.nigrum,T.squarrosum and R.sachalinensis were significantly higher than those of other species(P<0.05).The proportion of soil aggregates with particle size ranging from 2.00 mm to 5.00 mm in the treatment of R.sachalinensis was significantly higher than that of other plants(P<0.05).For the proportion of soil aggregates with particle size ranging from 1.00 mm to 2.00 mm,T.squarrosum showed no significant difference compared with R.nigrum,but was significantly higher than that of other plant species(P<0.05).In addition,the mean weight diameter of soil aggregates in the treatments of R.nigrum and T.squarrosum was higher than that of other plants,while the destruction rate of aggregates with diameter>1.00 mm was lower than that of other plants.It can be concluded that fine roots and small roots are the main factors affecting soil ag-gregate stability,which is achieved by promoting the aggregation of small-sized aggregates and increasing the proportion of large-sized aggregates with particle size ranging from 1 mm to 2 mm.The results of this study can provide a reference and basis for the selection and configuration of soil and water conservation vegetation in black soil regions.